Oil circuit breaker



Feb. 20, 1923.

I J. N. KELMAN OIL CIRCUIT BREAKER Filed Nov. 28, 1921 Patented Feb. 20,1923.

-. UNITED STATES PATENT OFFICE.

JOSEPH N. KELMAN, OF LOS ANGELES, CALIFORNIA.

OIL CIRCUIT BREAKER.

Application filed November 28, 1921. Serial No. 518,130.

To all whom it may concern:

' Be it known that I, JOSEPH N. KELMAN, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Improvement in Oil Circuit Breakthe circuit to persist, and for arcs to persist between the contacts "during the opening period. This results, in injury to the circuit breaker, due not only to the burningefi'ect of the arc, but also to the explosive effect of the gases generated, which may injure the tanks of the circuit breaker, or it may throw oil or hot gases from, the circuit breaker tank with injury to the attendants, or ad joining apparatus.

The principal object of my invention is to provide an oil circuit breaker which will promptly extinguish any arcs formed in the circuit breaker, and which will utilize the explosive force of one of these arcs to extinguish succeeding arcs. I

Further objects and advantages will be made evident hereinafter.

Referring'to the drawing, which is for illustrative purposes only,

Fig. 1 is a plan view of a three pole circuit breaker embodying my invention, the top and mechanism being removed from the right hand tank to better illustrate the interior structure.

Fig. 2 is an elevation, a portion of the right hand tank being shown in section to better. illustrate the interior structure.

Fig. 3 is a partial section on a plane, represented by the line 3-3, Fig. 2, and

Fig. 4 is a view of, the contacts in their openlposition.

In the form of the invention illustrated, there is shown a three pole circuit breaker, which is adapted to open the three phases of an ordinary transmission line. Each pole of thecircuit breaker consists of a tank 11 having two high tension bushings l2 which extend through a tight top 13 secured -on the tank 11. An operating shaft 15 extends through all three of the tanks 11, being operated by suitable'mechanism 16, which is standard in the art and forms nopart of the present invention.

Secured to the shaft 15, inside each of the tanks 11 are three cranks 20 to each of which is pivoted aconnecting. rod 21, which is secured on an insulator 22. The insulator 22 carries at its lower end a clevis 23 to which moving blades 24 are secured, these blades being guided by links 25, secured to a central insulator 26. There are three of these cranks 20, and three sets of the mechanism members 20 to 26, in each of-the tanks. The blades 25 make contact with stationary jaws 31, 32, 33, 34, 35 and 36, each carried on an insulator 30. It will be seen that the first set of blades 24 connect between the jaw 31 and the jaw 34, and that the secondset of blades connect the jaw 32 with the jaw 35, andthat the third set of blades connects the jaw 33 with the jaw'36. A conductor 40 passes through one of the high tension bushings, and a conductor 41 passes through the other. The conductor 40 is connected through a wire 42, with the jaw 33, and the conductor 41 is connected through a wire 43 with the jaw 34. The jaws on the insulators 31 and 32 are connected together by a wire 55 and the jawson the insulators 35 and 36 are connected together by a wire 56. I

With the switch closed, a circuit is established from the conductor 41, through the wire 43 to the jaw 34 across the first set of blades 24 to the jaw 31, through the wire 55 to the jaw 32, through the second set of blades 24 to the jaw 35, through the wire 56 to the'jaw 36, and through the third set of blades to the jaw 33, and through the wire 42 to the conductor 40.

When'it is desired to open the circuit, the shaft 15 isrotated in a counter clock-wise direction, as shown in Fig. 3, pulling up- 'wardly.on all three of the connecting rods 21 and raising each of the clevises23. This pulls upwardly on the inner ends of the blades 24 pulling them from the position,

shown in Fig. 3, into the position shown in Fig. 4. This opens the circuit of each of the jaws making in all six breaks in each phase of the circuit.

.Situa-ted between the jaws 31 and 33. 34

and 36 are tubes 60 which are formed of breaks are all in series in any with suitably formed slots 61 to'pern'iit the placing of the tubes 60 over the centrally and to allow thedisposed' jaws 32 and 35, engagement of the central blades 24 therewith as shown in Fig. 3. The blades 24, entering the jaws 32and 35, are arranged to open the circuit before any of the other blades open the circuit. As a result, the initial breaking of the circuit takes place at the central jaws 32 and 35, within the tubes 60. If the circuit is heavily overloaded, as generally occurs when these circuit breakers are called upon to act, there is a great tendency of an arc to form at these cont-acts and this are tends to vaporize the oil and to cause an expansion or explosion. This explosion, acting in all directions, forces oil to flow at a very high velocity through the tubes'60, the ends of these tubes being immediately adjacent to the other jaws, which open soon after the central jaws have opened. At the instant the outer jaws open, however, there is a very strong jet of oil moving across the space, immediately inside these jaws, this high velocity jet of oil tending to immediately wipe out or disperse any arcs which form on the outer jaws.

My invention is new and basic, in that I use the force of an explosion produced at the central jaws to prevent a persistence of any are formed at the outer jaws. Since the tank, it is evident that although the arc may persist at the central contact for a short space of time,.yet the greater the force of this arc, the less likelihood there is of an arc persisting between the outer jaws and their corresponding blades, and the more likelihood there is of the circuit being'opened at one or more of these points,

I claim as my invention:

1. In an oil circuit breaker, the combination of: atank in which the oil is carried; a plurality of sets of contacts in said tank,

each set being adapted to interrupt the circuit; and directional means by which the expansion due to opening the circuit at one of said sets of contacts forcing oil in the direction of another set of said contacts.

' 2. In an oil circuit breaker, the combination of: a tank in which the oil is carried; a plurality of sets of contacts in said tank, each set being adapted to interrupt the circuit; and an oil director so placed that the force of any explosion between one set of contacts forces oil in the direction of another set of contacts.

3. In an oil circuit breaker, the combination of: a tank in which the oil is carried; a plurality cuit; and a tube situated between two of said sets of contacts sudden expansion of the oil-at one end of said tube causes oil to flow toward one of said sets of contacts.

4;. In an oil circuit breaker, thecombination of: a tank in which the oil is carried; a plurality of sets of contacts in said tank, each set being adapted to" interrupt the circuit; means for opening one of said sets of contacts in advance 'of the others and means for using the expansion produced by the opening of said-set to extinguish an are on a set opening thereafter.

5. In an oil circuit breaker, the combination of: a tank in which the oil is carried; a plurality of .sets of contacts in said tank, each set being adapted to interrupt the ci'rsuit; means for opening one of said sets of contacts in advance of the other; and a directional means for utilizing the expansion produced by said opening set to force oil in the direction of the other set.

6. In an oil circuit breaker, the combination of: a tank in which the oil is carried; a plurality of sets of contacts in said tank, each set being adapted to interrupt the circuit; means for opening one of said sets of contacts in advance of the others; and an oil director so placed as to direct oil moving from said first opening set toward another one of said sets.

7. In an oil circuit breaker, the combination of: a tank in which the oil is carried;

a plurality of sets of contacts in said tank,

each set bein adapted to interrupt the'circuit; means ot opening one of said sets of contacts in advance of the others; and a tube having one open end adjacent to said first opening set and the other open end directed toward another one of said sets.

8. In an oil circuit breaker, the combination of: a tank in which the oil is carried; a plurality of sets of contacts in said tank, each set cuit; means or opening one of said sets of contacts in advance of the others; and a tube substantially enclosing the first opening of said sets having its. ends directing toward the other of said sets.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 21st day of November, 1921. JOSEPH N. KELMAN.

of sets of contacts insaid tank, each set being adapted to interrupt the cirandso' placed that a bein adapted to interrupt the cir- I 

